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-   -   Official "Science News" Thread (https://www.mersenneforum.org/showthread.php?t=12197)

xilman 2009-08-28 08:02

This [url]http://news.bbc.co.uk/2/hi/science/nature/8225491.stm[/url] is [i]really[/i] impressive!

A beautiful image of the electron density within a single pentacene molecule. Pentacene is five benzene rings fused in a linear fashion. Note the larger bumps at each end, corresponding to the C-H bonds.


Paul

davieddy 2009-08-28 15:58

[quote=xilman;187763]This [URL]http://news.bbc.co.uk/2/hi/science/nature/8225491.stm[/URL] is [I]really[/I] impressive!

A beautiful image of the electron density within a single pentacene molecule. Pentacene is five benzene rings fused in a linear fashion. Note the larger bumps at each end, corresponding to the C-H bonds.


Paul[/quote]
THX Paul.
Hope Davar55 is interested:smile:

D

davar55 2009-08-28 18:30

[quote=davieddy;187804]THX Paul.
Hope Davar55 is interested:smile:

D[/quote]

Thanks even for thinking of me.

Yes indeed these images show finer details and are,
of course, esthetically fascinating.
Does pentacene come from penta+(benz)ene or something else too?

davar55 2009-08-30 12:38

I tried Google and Wikipedia and couldn't get deeper than
acene for the etymology of pentacene.
So I'm currently assuming that these linearly linked
benzene ring molecules were just arbitrarily given their
designation as acenes because the letter c sounds nice there.

davar55 2009-09-03 13:50

[quote=davar55;188042]I tried Google and Wikipedia and couldn't get deeper than
acene for the etymology of pentacene.
So I'm currently assuming that these linearly linked
benzene ring molecules were just arbitrarily given their
designation as acenes because the letter c sounds nice there.[/quote]

Or maybe "c" for "cyclic ring".

sichase 2009-09-04 16:23

[quote=davar55;188521]Or maybe "c" for "cyclic ring".[/quote]

Actually, "pentacene" is named according to the IUPAC naming rules for cyclic hydrocarbons. Linear sequences of benzene rings are named according to the number of rings using the root "acene", which derives from "anthracene", the traditional name (probably of quite old origin, but I don't know the history) of the simplest member (3 rings) of the family. There are also tetracene, pentacene, etc.

You probably can really find this on the web if you search hard enough. But the fact that this kind of basic but specialized information is even hard to google just goes to show you how "skin deep" the web really is. The vast majority of human knowledge is not on-line... yet.

--Scott

davar55 2009-09-05 10:34

Anthracene apparently comes from anthrax + ene.

My good old paper dictionary mentions a Latin / French possible
derivation from anthracitis, a form of coal.
That would give the "c" I was looking for.

only_human 2009-11-07 23:12

Free Conference Nov 16th L.A. Convention Ctr.
 
I didn't feel that this warranted a thread in either Software or here as under Technology but this might be useful to someone; I might attend if my health allows . I signed up and can confirm that no money, credit card numbers or any other financial strings were attached to the registration of this specific session.

I have been using Mark Russinovich's nice utilities for years.

[URL="http://microsoftpdc.com/Sessions/WKSP08"]http://microsoftpdc.com/Sessions/WKSP08[/URL]

Windows 7 Developer Boot Camp
Landy Wang, Mark Russinovich, Arun Kishan at location Petree Hall D

Jump-start your Windows 7 experience by joining some of the top Windows 7 engineers, including Mark Russinovich [(I[I] have been using Mark Russinovich's nice utilities for years[/I].)] , Landy Wang, and Arun Kishan, for an intense, high quality boot camp. Whether you are looking to create more performant, reliable, or secure applications, or you are an application developer looking to leapfrog past your competition, this FREE Boot Camp can get you from zero to hero in less than eight hours! This fast-paced Windows 7 marathon will cover it all including: (1) Kernel and architectural improvements, (2) new shell integration points: taskbar, libraries and search, and (3) applied tips for getting the most out of today’s hardware with the sensor & location platform, multitouch, and the new graphics libraries (Direct2D, DirectX 11) that take advantage of the GPU. Whether you’re a C++, C# or Visual Basic developer, building a .NET or a Win32 application, we’ll give you actionable tips to get the most out of the Windows platform.

ewmayer 2009-11-13 18:07

Want Stronger Bones?
 
Just [url=http://well.blogs.nytimes.com/2009/11/11/phys-ed-the-best-exercises-for-healthy-bones/?em]jump up and down[/url] several times per day. (And maybe whack a heavy bag a couple times to get the arm bones, too).

The link with severe endurance sports and weaker bones is interesting.

CADavis 2009-11-13 21:09

[QUOTE] Most of the time, Dr. Barry says, “fragile bones don’t matter, from a clinical standpoint, if you don’t fall down."[/QUOTE]

:facepalm:

cheesehead 2009-11-15 15:46

[quote=CADavis;195769]:facepalm:[/quote]?

The complete paragraph (with my italics) is:

[quote]If hopping seems an undignified exercise regimen, bear in mind that it has one additional benefit: [I]It tends to aid in balance, which may be as important as bone strength in keeping fractures at bay.[/I] Most of the time, Dr. Barry says, “fragile bones don’t matter, from a clinical standpoint, if you don’t fall down.”[/quote]Similarly, in chess a theoretical weakness in one's position doesn't matter as long as the opponent has no way to attack it.


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